Spray gun



June 27, 1967 M. J. EULL. 3,327,949

SPRAY GUN Filed Sept. 17, 1965 3 Sheets-Sheet 2 United States Patent3,327,949 SPRAY GUN Marvin J. Eull, St. Michael, Minn, assignor to GrayCompany, Inc, Minneapolis, Minn., a corporation of Minnesota Filed Sept.17, 1965, Ser. No. 488,186 16 Claims. (Cl. 239-412) This inventionrel-ates to a spray gun for pain-ts, lacquers and like coating materialsand, more specifically, to an improved airless spray gun that includes adusting nozzle for directing a jet of compressed air against a surfaceto dislodge and remove particles of dust, dirt and the like from thesurf-ace prior to painting.

It has long been recognized that if paint is sprayed directly onto adusty or dirty surface, the quality of the finish will be impaired. Forthis reason, various equipment has been used in the past by spraypainters to clean the surfaces to be painted before spraying. However,as the cleaning equipment was not associated with the spray gun andusually could not be conveniently carried by the painter while he wasusing the spray gun, the pre-cleaning of the surfaces was a timeconsuming, and often neglected, operation since the painter was requiredto put aside his spray gun, pick up and use the cleaning equipment, andthen take up the spray gun again. Furthermore, since spray painters arerelatively highly paid workmen, the nonproductive time required for thiscleaning operation increases the cost of the painting and thus totalmanufacturing costs.

However, some skilled operators of conventional air spray guns havesometimes been able to reduce the time required for cleaning by usingtheir spray guns to clean the surfaces. This shortcut is possible sinceit was found that when the trigger of the air spray gun was barelydepressed, only a jet of compressed air escaped from the spray nozzle ofthe gun. Nevertheless, while this jet of compressed air could beutilized to clean a surface, the painter has to be extremely careful andskilled in order to obtain and maintain a jet that has sufficientvelocity and volume to clean satisfactorily but yet does not have anypaint entrained therein. Moreover, this method of using the spray gun toclean obviously could not be utilized with airless spray guns sincecompressed air is never present in or around the spray nozzle of thegun. Therefore, it is apparent that there has been a long-standing needin this industry for equipment which can be exepditiously andconveniently utilized to pre-clean surfaces to be painted and whichrequires a minimum of time and skill on the part of the painter forsatisfactory operation.

Accordingly, it is a primary object of the present invention to providea novel improved spray gun which permits the facile removal of dust anddirt from the surface to be painted by the gun, while eliminating theaforementioned loss of time and inconvenience heretofore associated withthis pre-cleaning operation.

Another object of the present invention is to provide a new spray gunhaving a dusting nozzle incorporated therein, which is completelyseparate from the paint spraying nozzle and which is adapted to emit ahigh velocity jet of compressed air therefrom that may be utilized toclean a surface before paint is applied thereto. A related object of thepresent invention is to provide an improved airless spray gun thatincorporates therein a dusting nozzle without significantly increasingthe size or weight of the gun or modifying the outer configuration ofthe gun.

Another object of the present invention is to provide an improved spraygun which includes a dusting nozzle that is arranged and directed sothat the jet of compressed air emitted therefrom impinges uponsubstantially 3,327,949 Patented June 27, 1967 ice the same portion ofthe surface as the paint being sprayed from the spray nozzle wheneverthe gun is held in its normal position for painting.

Still another object of the present invention is to provide a newimproved airless spray gun including a dusting nozzle and a valve forcontrolling the flow of compressed air through the dusting nozzle thatis separate from the conventional trigger mechanism utilized to controlthe flow of paint through the spray nozzle. A related object of thepresent invention is to provide a valve for con trolling the flow ofcompressed air through the dusting nozzle which cooperates with thevalve mechanism that controls the flow of paint through the spray nozzlewhereby simultaneous flow through both the dusting nozzle and spraynozzle is not possible.

Another object of the present invention is to provide an improvedairless spray gun in which compressed air from a single source isutilized, in a unique manner, to control both the flow of paint throughthe spray nozzle and to clean the surface to be painted, therebyminimizing the external connections to the gun and greatly simplifyingthe operation of the gun.

Another object of the present invention is to provide an improved spraygun which may be relatively inexpensively manufactured and competitivelymarketed and which substantially reduces the time and inconvenienceheretofore required to clean particles of dust, dirt and/ or old paintfrom a surface prior to the painting thereof.

These and other objects of my invention will be apparent from aconsideration of the accompanying specification, claims and drawings ofwhich:

FIGURE 1 is a vertical cross-sectional view of the improved spray gun ofthe present invention showing the components thereof in a position theyassume when the gun is not in use;

FIGURE 2 is a plan view, partially in vertical crosssection, of theimproved spray gun of the present invention showing the componentsthereof in the position they assume when a jet of paint is being sprayedfrom the spray nozzle;

FIGURE 3 is a plan view, partially in vertical crosssection, of theimproved spray gun of the present invention showing the componentsthereof in the position they assume when a jet of compressed air isbeing sprayed from the dusting nozzle;

FIGURE 4 is an enlarged vertical cross-sectional View of the spraynozzle assembly utilized in the improved spray gun of the invention;

FIGURE 5 is a partial horizontal, cross-sectional view of the triggermember showing the trigger stop member moved from the position shown inFIGURE 3; and

FIGURE 6 is a vertical cross-sectional view of the pilot valve assemblyshown in FIGURES 1-3.

Referring now to the drawings, the new improved spray gun of the presentinvention comprises a main stock 10, a butt or handle 12, a trigger 14,and a spray nozzle assembly 16. The stock 10 includes a hook 18 formedalong its upper edge from which the gun may be hung when not in use.

The nozzle assembly 16 is attached to the front end 20 of the stock 10and includes a main generally tubular member 22 having internally andexternally threaded ends 24 and 26 and a central portion 28 having arelatively larger external diameter. As shown, the end 24 closely fitsthrough an aperture 30 in the front end 20 of the stock so that thecentral portion 28 tightly abuts the front end 20, with a gasket 29positioned therebetween. Lock nut 32 or like fastening means cooperateswith external threads on the end 24 to Secure the tubular member 22 tothe stock 10. A locating pin 33 also extends between the central portion28 and the front end to prevent relative rotation therebetween and toinsure correct alignment of these parts. This construction permitsfacile interchange of the nozzle assembly so that the gun may beutilized with both circulating and noncirculating systems.

Referring now to FIGURE 4, a generally cylindrical member 34 has adiffuser tip insert 36 soldered within its front end and has itsrearward end threadedly received within the forward end 26 of thetubular member 22 with a sealing ring 38 positioned therebetween, asshown. Members 22 and 34 define an axial cavity 40 therebetween thatreceives paint, under pressure, from the lateral bore 42 formed in themember 22, as shown in FIGURE 1. The bore 42, in turn, is incommunication with a conduit 44, hereinafter more fully described, whichis press fit into the outer end of the bore.

The insert 36 has an axial, tapered bore 37 formed therein whichterminates at its front end in a standard elliptically shaped orifice. Aspherical surface is machined in the rear surface of the insert 36adjacent the rear, larger end of bore 37 in order to provide a flaredseat 39 for the needle valve assembly 46, hereinafter described, thatcontrols the flow of paint through the spray nozzle assembly 16.

An annular cap 48 is internally threaded at 50 so that it may be tightlythreaded onto the end 26 of the tubular member 22 and its forward end 52engages a flange 54 formed on a spray nozzle tip holder 56 whereby, asshown in FIGURE 4, the rear end of nozzle tip holder 56 is tightlypressed against the front end of the member 34, with a gasket 57positioned therebetween.

The nozzle tip holder 56 includes an axial bore 58, of two diameters,shown at 60 and 62, interconnected by a sloping shoulder 64. An annularspray nozzle tip 66 is positioned within the larger diameter portion 62so that its front peripheral edge abuts shoulder 64 and has an axialbore 67 therethrough with an orifice formed at its forward end which maybe of any conventional configuration or design. Also, an annular spacer68 is press fitted within the portion 62 0f the bore 58 adjacent thenozzle 66 and has a bore 69 formed therein coaxial with bore 67. Thespacer 68 also has a groove formed therein adjacent the bore 58 in whichan annular sealing ring 70 is positioned. Moreover, as noted above, theholder 56 is held tightly against the front end of the member 34 by thecap 48, with the gasket 57 preventing leakage therebetween. Of course,"whenever desired, the spray nozzle tip 66 may be quickly and easilyreplaced by a different sized tip by simply removing the cap 48.

The valve assembly 46, which controls the flow of paint through thenozzle assembly 12, comprises a ball valve 72 carried by the front endof an axially extending valve stem 74. The valve stem is guided in acounterbore 76 in the tubular member 22 and extends through a seal 78and a gland nut 80 that is threaded in the rear end 24 of the member 22,as shown in FIGURE 1. The stem 74 further extends rearwardly past thetrigger 14, through a bore 81 and into a motor chamber 82 formed in thestock portion 10, wherein its rear end is adjustably connected to apiston assembly 84 which is a component of a fluid motor that controlsthe movement of stem '74, as hereinafter described.

The valve assembly 46 is arranged so that when the spray gun is not inuse, the ball valve 72 is biased or pressed against the seat 39 formedin the insert blank 36 thereby closing or blocking the bore 37 therein.However, when the trigger 14 is moved rearwardly by the painter, thevalve stem 74 and thus the ball valve 72 are likewise moved rearwardly,away from the seat 39 thereby permitting paint, under high pressure, toflow at a high velocity from the cavity 40 through the bores 37, 67 and69 and through the orifices formed at the front ends of the bores 37 and67, whereby the paint may be atomized and sprayed on a surface to bepainted.

As shown in FIGURES 1-3, the trigger 14 consists of a symmetricallycurved piece of sheet metal 88, which is pivotally mounted at on thestock portion 10 so that the lower end thereof can be swung toward oraway from the handle 12. A generally trian-gularly shaped trigger safetystop 91, best shown in FIGURE 5, is mounted on the handle 12 and may bepivoted from the position shown to the position shown in FIGURE 5 whichis 90 from that shown in FIGURES 13 wherein its edges 92 contact thelongitudinal edges of the trigger piece 88 thereby preventing anyaccidental rearward movement of the trigger, for example, While theoperator is changing the spray nozzle tip. However, when the stop 91 isagain returned to the position shown in FIGURES l-3, the trigger may befreely moved rearwardly although, as shown in FIGURE 2, the stop 91 doesserve to limit the maximum rearward movement of the trigger. The stopmember 91 is provided with a triangular tooth 93 which is adapted to bebiased, by coil spring 94, into either of two triangular slots formed ina neck member 95 which is attached to the handle 12 as shown. Theseslots are disposed 90 apart and are shaped to hold the stop member ineither the operating position shown in FIGURES 13, or the safetyposition shown in FIGURE 5.

As noted above, movement of the trigger 14 controls the flow of paintthrough the spray nozzle assembly 16 by controlling the position of thevalve assembly 46. In fact, the movement of the trigger directlycontrols the position of a pilot valve essembly 96 which in turncontrols the position of the piston 84 within the fluid motor and thusthe position of the valve stem 74.

The fluid motor is positioned within chamber 82 which is defined by arecess 98 formed in stock portion 12 and a generally cup-shaped cap 100that is threadedly received within the recess 98 and has a cylindricalinner extension or side wall 102, as shown in FIGURE 2. When assembled,the thin side wall 102 of the cap extends almost to the bot-tom of therecess 98, and the piston 84, as hereinbefore noted, is connected to therear end of the valve stem 74 and is mounted for limited axial,reciprocal movement within the cap.

As seen from FIGURES 13, the piston 84 actually comprises two disks 104and 106 mounted on the threaded, rear end of the stem 74 and acup-shaped relatively flexible member 108 which is clamped tightlybetween the disks 104 and 106 so that its outer peripheral portionthereof is continuously in sealing engagement with the cylindrical wall102. Two sleeves 110 and 112 are also threaded onto the rear end of thestem 74 and are positioned adjacent the disks 104 and 106, respectively.The length and outer diameter of the sleeve 110 is such that this sleevemay slide within the bore 81 thereby acting as a guide and support forthe stem 74.

A coil compression spring 113 is positioned within the cap 100 betweenthe base 114- thereof and the disk 106. This spring urges the piston andthus the stem 74 in a forward or valve closing direction (to the leftwhen looking at FIGURES 1-3). Under certain conditions, to be described,the spring 113 is opposed by the pressure of the compressed air withinthe chamber 82, to the left hand side of piston 84, and a passage 116which interconnects the chamber 82 with the pilot valve assembly 96.

To prevent leakage of compressed air from the chamber 82, a sealing ring118 is positioned in the bore 81 about the stem 74, between sleeve 110and the forward end wall of bore 81, and sealing rings 120 and 122 arepositioned between the cap 100 and the stock 10. Also, as shown inFIGURES 13, a reduced diameter portion is formed on the side wall 102 ofthe cap 100 adjacent the base 114, so that an annular space 124 isdefined between the recess 98 and cap 100. This space is isolated fromboth the chamber 82 and the atmosphere by the sealing rings 120 and 122for reasons hereinafter explained. Further, a small central opening 125is drilled in the base 114 to vent the rear portion of the chamber 82 tothe atmosphere.

Referring now particularly to FIGURE 6, the pilot valve assembly 96noted above includes a valving element 126 which is reciprocally movablewithin axial bore 128 in an annular sleeve 130. This annular sleeve isthreaded Within a transverse bore 131 in the handle 12 and carriessealing rings 132 and 134 to prevent leakage between the bore 131 andthe sleeve. The axial bore 128 is two diame-, ters, indicated at 136 and138, which are interconnected by a sloping shoulder portion 140 andwhich is chamfered at 142 adjacent its inner end. Two sets of radiallyextending ports 144 and 146 are formed in the sleeve 130 and permitcommunication between the bore 138 and the passage 116 and between thebore 136 and an enlarged, longitudinally extending passage 148 in thehandle 12, respectively.

As shown in FIGURES l-3, a fitting 149 is threaded in the lower end ofthe passage 148 and is open to permit communication between the passage148 and the atmosphere whereby when valving element 126 is properlypositioned, the air under pressure within the chamber 82 may beexhausted to the atmosphere. The chamfered inner end 142 of the bore 138communicates with a chamber 150 which in turn communicates with a secondenlarged passage 152 in the handle 12. A fitting 154 is threaded intothe lower end of passage 152, and is adapted to receive a hose (notshown) or other conduit means which connects the spray gun with an airpump or other source of compressed air.

A bracket 156 is clamped between the fittings 149, 154 and the handle 12and extends a short distance toward the front of the gun Where itsupports a third fitting 158 which is connected to the other end of theconduit 44, described hereinabove. This fitting 158 is adapted tointerconnect the conduit 44 with a hose (not shown) or other conduitmeans which communicates with a paint pump or other source of paintunder pressure whereby the pressurized paint may be conveyed through thefitting and conduit 44 into the axial cavity 40 from whence it may passthrough the spray nozzle.

Referring again to the valve element 126, which may reciprocally movewithin the bores 136 and 138 of the sleeve 128, that element includes ahead portion 160 which contacts the trigger 14 and which has an outerdiameter that is substantially the same as the inner diameter of thebore 136 so as to provide a close sliding fit between the valve elementand the sleeve. A sealing ring 162 is carried by the head portion 160 toprevent leakage between the sleeve and the valve element.

Immediately to the right of-valve head 160 (as shown in FIGURES l-3 and6) are two valve lands 164 and 166 of different diameters which arepositioned in bore 136 and chamber 150, respectively, and which areinterconnected by a reduced diameter portion 168. The land 164cooperates with the shoulder .140 to control the flow of air betweenpassages 116 and 148 while the land 166 cooperates with the chamferedportion 142 to control the flow of compressed air from the passage 152(through chamber 150) to passage 116.

A relatively small diameter stud 169, with a bolt 170 threaded thereon,extends to the right from the land 166 and is surrounded by one end of acoil compression spring 171 which is positioned within the cavity 150.The spring abuts land 166 and urges the valve element 126 to the left(as shown in FIGURES 1-3) against the counteracting force applied to thevalve element by the trigger 14.

Thus, when the operator releases the trigger 14, spring 171 biases thevalve element 126 to the left until land 166 contacts the chamferedportion 142 and thereby blocks communications between passage 152 andchamber 82. However, at this time, land 164 is positioned to the left ofshoulder 140 thereby permitting chamber 82 to comrnunicate with theatmosphere through passages 116 and o 148 whereby spring 113 may biasthe piston 84, and thus the stem 74 and ball valve 72 to the left,blocking the flow of pressurized paint through the spray nozzle. Whenthe operator pulls the trigger 14 back toward the handle 12, the valveelement 126 is moved to the right thereby causing land 164 to contactshoulder and land 166 to move away from portion 142 wherebycommunication between chamber 82 and the atmosphere is blocked whilecompressed air from passage 152 may enter chamber 82. The compressed aircauses the piston 84 to move to the right against the bias of spring 113and this, in turn, causes the stem 74 and thus the ball valve 72 to moveaway from the seat 39 in the insert 36, as shown in FIGURE 4, therebypermitting flow of pressurized paint through the spray nozzle.

A counter bore 172 is formed in the stock 10 coaxial with the bore 131.This counter bore permits communication between the chamber and a shortpassage 174 which in turn communicates with the annular space 124 formedbetween the cap 100 and the bore 98 as hereinbefore described. A passage176 connects the annular space 124 with a dusting nozzle 17 8 which isthreaded into a bore drilled in the front of the hook 18. The dustingnozzle 178 is positioned in the hook 18 so that the jet of compressedair emitted therefrom will impinge upon the same porion of the surfaceto be painted as the spray of atomized paint from the spray nozzle, whenthe gun is held in the normal position for spray painting.

A valve 180 is positioned within cavity 150 to control the flow ofcompressed air from the cavity 150 through counter bore 172, passage174, annular space 124, passage 176 and the dusting nozzle 178. As shownin FIG- URES l-'3, the other end of the coil spring 171 abuts the valve18!) whereby the spring performs the dual function of biasing the valveelement 126 to the left while biasing the valve member 180 to the right.Valve 180 may be moved to the left and thus opened by the operatordepressing a button 182 which is rigidly connected to the valve 180 andwhich fits within counter bore 172.

As noted above, the stud 169 extends to the right from land 166 acertain distance toward valve 180. The length of this stud is such thatwhen the valve 180 is opened by depressing the button 182 or when thevalve element 126 is moved to the right by depressing the trigger 14,the right end of the stud and the valve 180 abut. Thus the stud acts asan interlock or stop in that it prevents the valve 180 from being openedwhenever the valve element 126 is in the position shown in FIGURE 2,viz. when passage 152 is in communication with chamber 82. Conversely,whenever the valve 180 is open, thereby permitting communication betweenpassage 152 and the dusting nozzle 178, the stud prevents the operatorfrom pulling back the trigger and shifting the valve element 126 fromthe position shown in FIGURE 3 to the position shown in FIGURE 2, viz.,prevents the operator from spraying paint through the spray nozzleassembly 16.

Thus, by correctly selecting the length of stud 169, it is apparent thatthe simultaneous emission of a jet of compressed air from dusting nozzle178 and a jet of atomized paint from the spray nozzle is not possible.

The operation of this novel spray gun may be summarized by referring toFIGURES 1-3. When the spray gun is not being utilized, the valveassembly 46, including the fluid motor in chamber 82, the pilot valve 96and the valve 180 are in the positions shown in FIGURE 1 wherein thechamber 82, to the left of piston 84, is vented to the atmosphere whileintercommunication between the compressed air in passage 152 and chamber82 and the dusting nozzle 178 is blocked by the pilot valve 126 andvalve 180, respectively. As shown in FIG- URE 2, when the operator pullsback the trigger 14, the pilot valve 126 is moved to the right so thatcommunication between the compressed air in passage 152 and the chamber82 is established whereby the valve assembly 46 is caused to move awayfrom the seat 39, as shown in FIGURE 4, and paint or like materials maypass through the nozzle and be hydraulically atomized. The dustingnozzle 178 may be utilized to clean foreign particles from a surface tobe spray painted by simply depressing the valve button 182 and thusopening the valve 180, as shown in FIGURE 3, whereby compressed air inpassage 152 may flow through passage 174, space 124, passage 176 and besprayed from. the nozzle 178. As shown in FIGURES 2 and 3, thearrangement of the valves 126 and 180 and the length of the stud 169positioned therebetween are such that the trigger l4 and the valvebutton 182 cannot be simultaneously depressed.

In view of the foregoing, it is apparent that the above described spraygun is a commercially significant improvement in that it not onlyprovides superior airless spraying but also incorporates therein adusting nozzle which may be utilized to clean the surface to be paintedprior to painting. The incorporation of the dusting nozzle in the spraygun considerably simplifies the problem of cleaning the surfaces to bepainted and concomitantly reduces the time needed for the pre-cleaningof the surfaces thereby significantly increasing the efficiency andproductivity of the painter.

Furthermore, the novel spray gun of the present invention utilizescompressed air from the same source to control both the flow ofpressurized paint through the spray nozzle and to pre-clean the surfaceto be painted, thereby greatly simplifying the operation of the gun andminimizing the external connections required therefor.

Moreover, through the unique cooperation between the valves controllingthe flow through the dusting nozzle and the valve controlled by thetrigger, simultaneous flow through the dusting nozzle and the spraynozzle is prevented, thereby eliminating the possibility of anaccidental simultaneous discharge through both of these nozzles.

While I have shown certain specific embodiments of my invention forpurposes of illustration, it is to be understood that the scope of myinvention is limited solely by the appended claims.

I claim as my invention:

1. An airless spraying apparatus for coating materials, comprising: abody having first and second chambers formed therein; first nozzle meansmounted on said body; means for supplying a coating material under pressure to said first nozzle means; first valve means for controlling theflow of coating material through said first nozzle means therebypermitting said material to be sprayed onto a surface to be coated; saidfirst valve means including fluid pressure responsive means positionedwithin said first chamber; means for supplying a fluid under pressure tosaid second chamber; second valve means for permitting controlledcommunication between said second and first chambers; second nozzlemeans mounted on said body; and means for permitting communicationbetween said second chamber and said second nozzle means including athird valve means for controlling the flow of said pressurized fluidthrough said second nozzle means.

2. An airless spraying apparatus for coating materials comprising: abody having first and second chambers formed therein; first nozzle meansmounted on said body; means for supplying a coating material underpressure to said first nozzle means; first valve means for controllingthe flow of coating material through said first nozzle means therebypermitting said material to be sprayed onto a surface to be coated;fluid pressure responsive means positioned within said first chamber andoperatively connected with said first valve means; means for supplying afluid under pressure to said second chamber; second valve means forpermitting controlled communication between said second and firstchambers; second nozzle means mounted on said body; means for permittingcommunication between said second chamber and said second nozzle meansincluding a third valve means for controlling the flow of saidpressurized fluid through said second nozzle means for cleaning saidsurface; and means for preventing simultaneous flow through both saidfirst and second nozzle means.

3. An airless spraying apparatus for coating materials comprising: abody having first and second chambers formed therein; first nozzle meansmounted on said body; means for supplying a coating material underpressure to said first nozzle means; first valve means for controllingthe flow of coating material through said first nozzle means therebypermitting said material to be sprayed onto a surface to be coated;fluid pressure responsive means positioned within said first chamber andoperatively connected with said first valve means; means for supplying afluid under pressure to said second chamber; second valve means forpermitting controlled communication between said second and firstchambers whereby said pressurized fluid causes said first valve means tomove to permit flow through said first nozzle means; second nozzle meansmounted on said body; means for permitting communication between saidsecond chamber and said second nozzle means including a third valvemeans for controlling the flow of said pressurized fluid through saidsecond nozzle means for cleaning said surface; and means cooperatingwith said second and third valve means for preventing simultaneous flowthrough both said first and second nozzle means.

4. An airless spraying apparatus for coating materials comprising: abody having first and second chambers formed therein; first nozzle meansmounted on said body; means for supplying a coating material underpressure to said first nozzle means; first valve means for controllingthe flow of coating material through said first nozzle means therebypermitting said material to be sprayed onto a surface to be coated;fluid pressure responsive means positioned within said first chamber andoperatively connected withsaid first valve means; means for supplyingfluid under pressure to said second chamber; second valve means forpermitting controlled communication between said second and firstchambers; second nozzle means mounted on said body, said second nozzlemeans being directed in the same direction as said first nozzle meanswhereby spray emitted from said first and second nozzle means impingesagainst substantially the same portion of the surface to be coated;means for permitting communication between said second chamber and saidsecond nozzle means including a third valve means for controlling theflow of said second pressurized fluid through said second nozzle meansfor cleaning said surface; and means for preventing simultaneous flowthrough bot-h said first and second nozzle means.

5. An airless spray gun for liquid coating materials comprising: a bodyhaving first, second, third and fourth chambers formed therein; meansfor supplying pressurized coating material to said first chamber, afirst nozzle mounted on said body in communication with said firstchamber and having an orifice through which said material may pass,thereby atomizing said material and directing the same onto a surface tobe coated; a first valve means for controlling the flow through saidorifice; a fluid presure responsive mot-or means movable within saidsecond chamber and operatively connected with said first valve means,whereby said motor means may move said first valve means between aclosed position and an open position in which said material may passthrough said orifice; means for supplying a pressurized gas to saidthird chamber; means for exhausting said fourth chamber; second valvemeans movable between a first position wherein said second chamber is incommunication with said third chamber whereby said motor means movessaid first valve means to an open position and a second position whereinsaid second chamber is in communica tion with said fourth chamberwhereby said motor means moves said first valve means to said closedposition; a second nozzle mounted on said body; conduit means connectingsaid third chamber with said second nozzle and thirdvalve means forcontrolling the flow of pressurized gas from said third chamber throughsaid second nozzle.

6. An airless spray gun for liquid coating materials comprsing: a bodyhaving first, second, third and fourth chambers formed therein; meansfor supplying pressurized coating material to said first chamber; afirst nozzle mounted on said body in communication with said firstchamber and having an orifice through which said material may pass,thereby atomizing said material and directing the same onto a surface tobe coated; a first valve means for controlling the flow through saidorifice; a fluid pressure responsive motor means movable within saidsecond chamber and connected to said first valve means whereby saidmotor means may move said first valve means between a closed positionand an open position in which said material may pass through saidorifice; means for supplying compressed air to said third chamber; meansfor exhaustnig said fourth chamber; second valve means movable between afirst position wherein said second chamber is in communication with saidthird chamber whereby said motor means moves said first valve means toan open position and a second position wherein said second chamber is incommunication with said fourth chamber whereby said motor means movessaid first valve means to the closed position; a second nozzle mountedon said body; conduit means connecting said third chamber with saidsecond nozzle; third valve means for controlling the flow of compressedair from said third chamber through said second nozzle for cleaning saidsurface and means for preventing simultaneous flow through both saidorifice and said second nozzle.

7. A spray gun, as described in claim 6 wherein said first and secondnozzles are pointed in substantially the same direction whereby flowthrough both said first and second nozzles may be directed ontosubstantially the same portion of said surface.

a 8. An airless spray gun for liquid coating materials comprising: abody having first, second, third and fourth chambers formed therein;means for supplying pressurized coating material to said first chamber;a first nozzle mounted on said body in communication with said firstchamber and having an orifice through which said material may pass,thereby atomizing said material and directing the same onto a surface tobe coated; a first valve means for controlling the flow through saidorifice; a fluid pressure responsive motor means movable within saidsecond chamber and connected with said first valve means whereby saidmotor means may move said first valve means between a closed positionand an open position in which said material may pass through saidorifice; means for supplying pressurized gas to said third chamber;means for exhausting said fourth chamber; second valve means movablebetween a first position wherein said second chamber is in communicationwith said third chamber whereby said motor means moves said first valvemeans to an open position and a second position wherein said secondchamber is in communication with said fourth chamber whereby said motormeans moves said first valve means to the closed position; a secondnozzle mounted on said body; conduit means connecting said second nozzlewith said third chamber, third valve means for controlling the flow ofpressurized gas from said third chamber through said second nozzle andmeans positioned between and cooperating with said second and thirdvalve means for preventing simultaneous flow through both said orificeand said second nozzle.

9. An airless spray gun for liquid coating material comprising: a bodyhaving first, second, third and fourth chambers formed therein; meansfor supplying pressurized coating material to said first chamber; afirst nozzle mounted on said body in communication with said firstchamber and having an orifice through which said material may pass,thereby atomizing said material and directing the same onto a surface tobe coated; a first valve means for controlling the flow through saidorifice; a fluid pressure responsive motor means movable within saidsecond chamber and connected with said first valve means whereby saidmotor means may move said first valve means between a closed positionand an open position in which said material may pass through saidorifice; means for supplying pressurized gas to said third chamber;means for exhausting said fourth chamber; sec-0nd valve means movablebetween a first position wherein said second chamber is in communicationwith said third chamber whereby said motor means moves said first valvemeans to an open position and a second position wherein said secondchamber is in communication with said fourth chamber whereby said motormeans moves said first valve means to the closed position; a secondnozzle mounted on said body; conduit means connecting said third chamberwith said second nozzle; third valve means for controlling the flow ofpressurized gas from said third chamber through said second nozzle andmeans carried by said second valve means and arranged to cooperate withsaid third valve means whereby when said second valve means is in saidfirst position, said third valve means is prevented from permitting flowthrough said second nozzle and whereby when said third valve means isopened to permit flow through said second nozzle, said second valvemeans is prevented from being moved from said second to said firstposition.

10. An airless spray gun for spraying liquid onto a remote surfacecomprising: a body; a first nozzle mounted on said body; means forsupplying pressurized coating material to said first nozzle whereby saidmaterial may flow through said first nozzle and be sprayed onto asurface to be coated; first valve means adjustably movable forcontrolling the flow of coating material through said first nozzle; apressure responsive motor means mounted in said body and operativelyconnected with said first valve means for positioning said first valvemeans; means for supplying pressurized gas to said body; means forexhausting said gas from said body, second valve means including apiston mounted in said body and selectively movable between a firstposition, wherein said gas supply means is interconnected with motormeans thereby causing said motor means to move said first valve means sothat said material may flow through said first nozzle and a secondposition wherein said gas exhausting means is interconnected with saidmotor means thereby causing said motor means to move said first valvemeans so that said material is prevented from flowing through said firstnozzle; means for biasing said piston to said first position; manuallyoperated trigger means for moving said piston from said first positionto said second position; a second nozzle mounted in said body; a passageconnecting said gas supply means with said second nozzle whereby saidgas may flow through said second nozzle and be sprayed onto said surfacefor cleaning the same; and third valve means including a normally closedvalve member selectively movable in said body from an open positionwherein communication is permitted between said gas supply means andsaid second nozzle and a closed position wherein communication isprevented between said gas supply means and said second nozzle.

11. A spray gun, as described in claim 10, wherein said first and secondnozzles are pointed in substantially the same direction whereby flowthrough both said first and second nozzles may be directed ontosubstantially the same portion of said surface.

12. An airless spray gun for spraying liquid onto a remote surfacecomprising: a body; a first nozzle mounted on said body; means forsupplying pressurized coating material to said first nozzle whereby saidmaterial may flow through said first nozzle and be sprayed onto asurface to be coated; first valve means adjustably movable forcontrolling the flow of coating material through said first nozzle; apressure responsive motor means mounted in said body and operativelyconnected with said first valve means for positioning said first valvemeans; means for supplying pressurized gas to said body; means forexhausting said gas from said body, second valve means including apiston mounted in said body and selectively movable between a firstposition, wherein said gas supply means is interconnected with motormeans thereby causing said motor means to move said first valve means sothat said material may flow through said first nozzle and a secondposition wherein said gas exhausting means is interconnected with saidmotor means thereby causing said motor means to move said first valvemeans so that said material is prevented from flowing through said firstnozzle; means for biasing said piston to said first position, manuallyoperated trigger means for moving said piston from said first positionto said second position; a second nozzle mounted in said body; a passageconnecting said gas supply means with said second nozzle whereby saidgas may flow through said second nozzle and be sprayed onto said surfacefor cleaning the same; third valve means including a normally closedvalve member selectively movable in said body from an open positionwherein communication is permitted between said gas supply means andsaid second nozzle and a closed position wherein communication isprevented between said gas supply means and said second nozzle; andmeans for preventing the opening of said valve member whenever saidpiston is in said second position and preventing said piston from beingmoved from said first position to said second position, whenever saidvalve member is in its open position.

13. An airless spray gun for spraying liquid onto a remote surfacecomprising: a body; a first nozzle mounted on said body; means forsupplying pressurized coating material to said first nozzle whereby saidmaterial may flow through said first nozzle and be sprayed onto asurface to be coated; first valve means adjustably movable forcontrolling the flow of coating material through said first nozzle; apressure responsive motor means mounted in said body and operativelyconnected with said first valve means for positioning said first valvemeans; means for supplying compressed air to said body; means forexhausting said compressed air from said body, second valve meansincluding a piston mounted in said body and selectively movable betweena first position, wherein said air supply means is interconnected withmotor means thereby causing said motor means to move said first valvemeans so that said material may flow through said first nozzle and asecond position wherein said air exhausting means is interconnected withsaid motor means thereby causing said motor means to move said firstvalve means so that said material is prevented from flowing through saidfirst nozzle; means biasing said piston to said first position; manuallyoperated trigger means for moving said piston from said first positionto said second position; a second nozzle mounted in said body; a passageconnecting said air supply means with said second nozzle whereby saidcompressed air may flow through said second nozzle and be sprayed ontosaid surface for cleaning the same; third valve means including anormally closed valve member selectively movable in said body from anopen position wherein communication is permitted between said air supplymeans and said second nozzle and a closed position wherein communicationis prevented between said air supply means and said second nozzle, saidvalve member being positioned coaxially with said piston; resilientbiasing means positioned between said piston and said valve member forurging said piston to said first position and said valve member to itsclosed position; said piston having a portion projecting therefromtoward said valve member and arranged so that saidpiston cannot be movedfrom said first position tosaid second position whenever said valvemember is in its open position.

14. A spray gun as described in claim 13 wherein said valve member maybe moved from its closed position to its open position by manuallymovable means separate from said trigger means and wherein an elongatedshaft interconnects said first valve means with said motor means theaxis of said shaft being coaxial with the longitudinal axis of saidfirst nozzle means.

15. A spray gun as described in claim 13 wherein said body includes ahook-like portion formed integrally therewith, and said second nozzle ismounted in said hook-like portion.

16. A spray gun, as described in claim 13, wherein said first and secondnozzles are pointed in substantially the same direction whereby flowthrough both said first and second nozzles may be directed ontosubstantially the same portion of said surface.

No references cited.

EVERETT W. KIRBY, Primary Examiner.

1. AN AIRLESS SPRAYING APPARATUS FOR COATING MATERIALS, COMPRISING: ABODY HAVING FIRST AND SECOND CHAMBERS FORMED THEREIN; FIRST NOZZLE MEANSMOUNTED ON SAID BODY; MEANS FOR SUPPLYING A COATING MATERIAL UNDERPRESSURE TO SAID FIRST NOZZLE MEANS; FIRST VALVE MEANS FOR CONTROLLINGTHE FLOW OF COATING MATERIAL THROUGH SAID FIRST NOZZLE MEANS THEREBYPERMITTING SAID MATERIAL TO BE SPRAYED ONTO A SURFACE TO BE COATED; SAIDFIRST VALVE MEANS INCLUDING FLUID PRESSURE RESPONSIVE MEANS POSITIONEDWITHIN SAID FIRST CHAMBER; MEANS FOR SUPPLYING A FLUID UNDER PRESSURE TOSAID SECOND CHAMBER; SECOND